Improvement of Schottky Contacts of Gallium Oxide (Ga2O3) Nanowires for UV Applications.

Badriyah Alhalaili,M Saif Islam,Ileana Nicoleta Popescu,Ruxandra Vidu,Luige Vladareanu,Ahmad Al-Duweesh

doi:10.3390/s22052048

Abstract

Interest in the synthesis and fabrication of gallium oxide (Ga2O3) nanostructures as wide bandgap semiconductor-based ultraviolet (UV) photodetectors has recently increased due to their importance in cases of deep-UV photodetectors operating in high power/temperature conditions. Due to their unique properties, i.e., higher surface-to-volume ratio and quantum effects, these nanostructures can significantly enhance the sensitivity of detection. In this work, two Ga2O3 nanostructured films with different nanowire densities and sizes obtained by thermal oxidation of Ga on quartz, in the presence and absence of Ag catalyst, were investigated. The electrical properties influenced by the density of Ga2O3 nanowires (NWs) were analyzed to define the configuration of UV detection. The electrical measurements were performed on two different electric contacts and were located at distances of 1 and 3 mm. Factors affecting the detection performance of Ga2O3 NWs film, such as the distance between metal contacts (1 and 3 mm apart), voltages (5–20 V) and transient photocurrents were discussed in relation to the composition and nanostructure of the Ga2O3 NWs film.

Highlights

Wide bandgap-based semiconductors are suitable for harsh environmental applications, such as in UV photodetectors, especially high-powered electronics and optoelectronics that operate in harsh environmental applications, such as solar UV monitoring, communications, and the detection of missiles [1–4]
The photodetection response of Ga2O3 nanostructures grown on Ag-coated quartz increased by almost two orders of magnitude compared to the Ga2O3 nanostructures grown on bare quartz, while the ratio of photocurrent to dark current was almost 9-times higher, leading to a more sensitive detection of UV light
By switching a UV light source on and off, a fast transient response was attained by Ga2O3 nanowires on quartz obtained in the presence of Ag catalyst because of higher carrier transport

Summary

Introduction

Wide bandgap-based semiconductors are suitable for harsh environmental applications, such as in UV photodetectors, especially high-powered electronics and optoelectronics that operate in harsh environmental applications, such as solar UV monitoring, communications, and the detection of missiles [1–4]. The photodetection response of Ga2O3 nanostructures grown on Ag-coated quartz increased by almost two orders of magnitude compared to the Ga2O3 nanostructures grown on bare quartz, while the ratio of photocurrent to dark current was almost 9-times higher, leading to a more sensitive detection of UV light. In this manuscript, we communicate the first results of the influence of different metal contacts to improve the electrical properties of Ga2O3 NWs and to study their photoconductance. We discuss the factors that affect the detection process of Ga2O3 NWs material, such as the distance between metal contacts, voltages, and the transient photocurrent

Materials and Methods

Distance between Probes

Film Thickness

Transient Photocurrent

Conclusions